Geseklschaft



Sept. 22, 1925. 1,554,927

H. -SUNDHAUSSEN EXCITING CIRCUITS Original Filed Feb. 18, 1915 Patented Sept. 22, 1925.

UNITED STATES PATENT OFFICE.

HERMANN SUNDHAUSSEN, OF ESSEN, GERMANY, ASSIGNOR T0 FRIED. KRUPP AKTIEN- GESELLSCHAFT, OF ESSEN-ON-THE-RUHR, GERMANY.

EXCITING CIRCUIT.

Originalapplication filed. February 18, 1915, Serial No. 9,348. Divided and this application filed May 2,

Serial No. 466,318.

(GRANTED UNDER THE PROVISIGNE OF THE ACT OF MARCH 3, 1921, 41 STAT. L, 1313.)

To all whom it may concern:

Be it known that I, HERMANN SUNDHAUS- SEN, residing at Essen, Germany, a citizen of the German Republic, have invented a certain new and useful Improvement in Exciting Circuits, of which the following is a specification.

The present invention relates to connections for the exciting of circuits which con tain a member having self-induction and being intended for relatively strong exciting currents of Very short duration only. The object of this invention is to provide a connection of this character which is so arranged that the exciting current diminishes automatically a short time after switching in said member so that the circuit may be interrupted practically without sparks. This object is attained according to the invention by connecting the member having self-induction to a source of direct current by means of a switch and over the intermediate armature 01" a direct current motor not being loaded with any exterior mechanical load. This application is a division of my application Serial No. 9,348, filed February 18th, 1915.

One embodiment of the present invention .is illustrated in the accompanying drawing giving diagrammatic representation of a connection intended for the exciting circuit of a releasing magnet, for instance a gun firing magnet.

In the accompanying drawing A denotes the exciting coil of the releasing magnet. This coil is connected with a continuous current network D over a freely revoluble armature B of a small electromotor and a switch C. The electromotor has an ex ternally excited main field winding B fed from the continuous current network, the action of said main field winding being adjustable by means of a rheostat E, and an auxiliary field winding B situated in the armature circuit together with a rheostat F appertaining thereto.

The described connection operates as follows:

Before the exciting of the magnet, the switch C is situated in the open position, as indicated on the drawing, and the armature B of the electromotor B B B is consequently at rest. l/Vhen the magnet is to be excited, the circuit is closed by means of the switch G, whereupon the electromotor B B B starts. As the counter-electromotive force of the armature B of the motor, is very small at the beginning of the rotation, the coil A at once takes up a very strong current, which effects a quick exciting of the magnet. The rate of increase in the speed of the armature B is the same as the increase of its counter-electromotive force, whilst the current strength is correspondingly diminished in the armature circuit containing the coil A. WVhen the armature B has attained its greatest speed, the current strength in the coil A has then sunk to such a low degree, that no injurious breaking sparks can form on interrupting the switch C. As a consequence, the interruption takes place practically without sparks. The described connection also permits a convenient adjustment of the magnetic retardation. This adjustment may be accomplished either with the assistance of the rheostat E or the rheostat F, as the magnitude of the resistance in the rheostat E influences the time constant of the circuit, and the magnitude of the resistance in the rheostat F influences the starting time of the electric motor and consequently also the time for the current to pass over thecoil A.

The arrangement above described offers a simple and convenient means for temporarily exposing a magnet coil to a very strong exciting current without using a coil constructed for constant load and without having need to interrupt a current of considerable intensity. Since the duration of the exciting period of a releasing magnet coil is usually only a fractional part of a second, such coil may receive a current many times stronger than the current admissible for constant load. The quickly rising counter electromotive force of the armature inserted in the circuit in series with the magnet coil is a very convenient means for automatically reducing the strength of the exciting current to a value which permits to break the circuit without any sparks.

I claim 1. In combination with a circuit which includes a member having self-induction and intended for working currents of short duration only, a direct current motor, said motor having an armature not being loaded with any exterior mechanical load, a source of direct current, said member and said armature being adapted to be connected in series to said source and a control switch for connecting said member and said armature in series to said source, and dis connecting said series connection after said motor has started.

2. In combination with a circuit which includes a number having self-induction and intended for working currents of short duration only, a direct current motor, said motor having an armature not being loaded with any exterior mechanical load, a source of direct current, said member and said armature being adapted to be connected in series to said source and a control switch for connecting said member and said arma ture in series to said source, and disconnectingsaid series connection after said motor has started; the field winding of said motor being connected to said source and having so weak a saturation that the field strength is approximately proportionate with the exciting current strength in said Winding.

3. In combination with a. circuit which includes the winding of a releasing magnet intended for excitation of short duration only, a direct current motor, said motor having an armature not being loaded with any exterior mechanical load, a source of direct current, and a control switch for connecting said magnet winding and said armature in series to said source and disconnecting same after said motor has started.

4:. A method of making a sparkless interruption of a. circuit comprising a magnet coil and intended for receiving an exciting current of short duration only, consisting in first exposing said coil to the full strength of a voltage source and then diminishing the current in said coil to a minin'ium, when the circuit may be broken without sparks, this diminishing of current being accomplished by the insertion between said source and said coil of a direct current motor not being loaded with any exterior mechanical load.

5. A method of sparklessly interrupting a circuit comprising a magnet coil and a direct current motor, the ari'nature of said motor being connected in series to said magnet coil, consisting in first exposing said coil to the full strength of a current source connected to said circuit, and then interrupting said circuit after said motor has at tained substantially its highest speed.

The -foregoing specification signed at Essen, Germany, this 2nd day of March, 1921.

HERMANN SUNDHAUSSEN. 

